package com.demo.listener;

import org.apache.commons.fileupload.FileItem;
import org.apache.commons.fileupload.FileItemFactory;
import org.apache.commons.fileupload.FileUploadException;
import org.apache.commons.fileupload.disk.DiskFileItemFactory;
import org.apache.commons.fileupload.servlet.ServletFileUpload;

import java.io.File;
import java.io.IOException;
import java.util.List;

/**
 * @author WuLiangHang
 */
@javax.servlet.annotation.WebServlet(name = "FileUploadServlet", urlPatterns = "/upload.do")
public class FileUploadServlet extends javax.servlet.http.HttpServlet {
    @Override
    protected void doPost(javax.servlet.http.HttpServletRequest request, javax.servlet.http.HttpServletResponse response) throws javax.servlet.ServletException, IOException {
        request.setCharacterEncoding("UTF-8");
        response.setContentType("text/html; charset=UTF-8");
        //1.先判断上传的数据是否为多段数据（只有是多段的数据 才是文件上传的）
        if (ServletFileUpload.isMultipartContent(request)) {
            //创建FileItemFactory工厂实现类
            FileItemFactory fileItemFactory = new DiskFileItemFactory();
            //创建用于解析上传数据的工具类ServletFileUpload类
            ServletFileUpload servletFileUpload = new ServletFileUpload(fileItemFactory);
            try {
                //解析上传的数据 得到每一个表单项FileItem
                List<FileItem> list = servletFileUpload.parseRequest(request);
                //循环判断 每一个表单项 是普通类型 还是上传的文件
                for (FileItem fileItem :
                        list) {
                    if (fileItem.isFormField()) {
                        //普通表单项
                        System.out.println("表单项的name = " + fileItem.getFieldName());
                        System.out.println("表单项的value = " + fileItem.getString("UTF-8"));
                    } else {
                        //上传的文件
                        System.out.println("表单项的name = " + fileItem.getFieldName());
                        System.out.println("上传的文件名 = " + fileItem.getName());
                        fileItem.write(new File("D:\\upload\\" + fileItem.getName()));
                    }
                }
            } catch (FileUploadException e) {
                e.printStackTrace();
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
    }
}
